/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package com.google.code.twiddling.core.command.builtin;

import java.util.List;

import com.google.code.twiddling.core.clp.Argument;
import com.google.code.twiddling.core.command.AbstractCommand;
import com.google.code.twiddling.core.command.CommandContext;
import com.google.code.twiddling.core.command.Command;

/**
 * @author <a href="mailto:jeff.yuchang@gmail.com">Jeff Yu</a>
 *
 */
@Command(name="echo", description="echo variables that stored in the twiddling environment" ,
		 usage="echo [variable]..." , example = "echo $JAVA_HOME $MAVEN_HOME")
public class EchoCommand extends AbstractCommand {
	
	@Argument
	private List<String> arguments;
	
	@Override
	public void doExecute(CommandContext context) throws Exception {
		if (arguments != null) {
			for (String argument : arguments) {
				if (argument.startsWith("$")) {
					String key = argument.substring(1);
					context.getIO().getOut().print(context.getEnvironment().getVariable(key));
				} else {
					context.getIO().getOut().print(argument);
				}
				context.getIO().getOut().print(" ");
			}
		}
		context.getIO().getOut().println();
	}

}
